package servlet;

import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.FileInputStream;
import java.io.IOException;

@WebServlet("/upload/*")
public class GetUploadServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    //获取资源地址
        final String uri = request.getRequestURI();
        //提取文件名
        final String filename = uri.replaceAll(".+/upload/(.+)", "$1");

        //设置返回的内容类型
        //html==>text/html , jpg==>image/jpeg
        final String mimeType = request.getServletContext().getMimeType(filename);
        response.setContentType(mimeType);
        //将文件返回给浏览器
        //java io 流
        String path=UploadImageServlet.IMAGE_PATH+filename;

        try(FileInputStream fis =new FileInputStream(path)){
            byte[] buffer =new byte[1024];
            int count;
            final ServletOutputStream out = response.getOutputStream();
            while ((count = fis.read(buffer))>-1){
                out.write(buffer,0,count);
            }

        }
    }
}
